Hi,

A fellow MCM-Exchange (Devin L. Ganger) made a blog posting clarifying the security requirements around the needed FSW for the Exchange 2010 Database Availability Group.

-->  http://www.thecabal.org/2009/12/busting-the-exchange-trusted-subsystem-myth/

If you where planning to add the machine account of the server hosting your FSW share to the Exchange Trusted Subsystem then think again and read his blog posting.

If your not up for the reading, the message is don't do it, simply add the Exchange Trusted Subsystem to the local administrators group of the server hosting the FSW Share and as soon as you add the second member in the DAG the share get's created automatically.